Iris diaphragm



F. MEYER.

IRIS DIAPHRAGM.

APPLICATION man was, 1921.

1 ,41 1 ,21 9, Patented Mar. 28, 1922.

UNITED STATES PATENT OFFICE.

FRANZ MEYER, OF JENA, GERMANY, ASSIGNOR TO THE FIRM OF CARL ZEISS, OF JENA,

. GERMANY.

IRIS DIAPHRAGM.

Specification of Letters Patent.

Patented Mar. 28, 1922.

- Application filed August 8, 1921. Serial No. 490,735

(GRANTED UNDER THE PROVISIONS THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

, Germany, have invented a new and useful Iris Diaphragm (for which I have filedan application in Germany January 26, 1918, Patent No. 305,626,) of which the following is a specification.

The flat, adjustable lamellae of an irisdiaphragm, on the latter being brought into a horizontal position or one approaching the same, are inclined to sag owing to their weight.

lVith large diaphragms as used, ii, for search-lights or for large astronomical telescopes, this property may lead to rendering the opening and closing of the diaphragm difiicult or entirely impossible because the construction of the d iris-d iaplu'ag rms does not admit of strengthening along with the enlargement of the diaphragm in conformity to its diameter the lamell'ee accordingly.

According to the invention the above mentioned drawback may, however, be obviated by joining each of the lamellee to a supporting arm, rotatably disposed about a journal which is connected to the collar carrying the journals otthe lamellae in such amanner that its axis coincides with that of the jour nal of the lamella united with the respective supporting arm.

The drawing shows a constructional exam ple of a diaphragm corresponding to the invention, viz. in Fig. 1 in a section drawn along theline 1-1 in Fig. 2, whilst Figs. 2 and 3 show a plan elevation each. In Fig. 2 the lamellee are drawn in the position corresponding to the smallest and in Fig. '3' in that corresponding to the largest aperture of the diaphragm.

The lamellee marked a of which, in order to attain a clear representation, only three are shown in the drawing and which, for the same purpose, proportional to their length are drawn considerably broader than 45 they are generally carried out, are supported by two collars b and c, disposed in a casing d. The first of the said two collars, b, is made of one piece with the casing, i. e. rigidly connected to the same whilst the second, c, is rotatably disposed in this casing. Each of the lamellae is fixed to the collar 5 by means of a pivot e, which is firmly riveted to the lamella but rotatable in the collar. The collar 0, by the rotation of which the diaphragm is to be opened and closed, is provided with radial slits 7', each of which serves as a guide of a bolt g, riveted to one of .the lamellee. In addition, on the cam'ng (l an annular body it is rigidly disposed to which a number of cylindrical pivots 71 equal to the numberof the lamellee is fixed in such a manner that the axes of these pivots coin title with those of the journals (2. Besides, about the pivots arms/r: are rotatably disposed, each of thesebeing fixed at its free end to that lamella. the axis of rotation of which coincides with its own. As it is obvious, a strengthening of the lamellee, counteracting to the sagging, is effected by means of the supporting arms is, without impairing thereby the freedom of motion of the said lamell'ze.

I claimi In an iris-diapl1ragm a set of lamellee, each of which is rotatably disposed on a collar and coacts with a second collar, the two collars being rotatable relatively to each other, and a set of supporting arms, each of which is connected at one of its ends to one of the said lamellae and rotatably disposed on its other end about an axis coinciding with the axis of rotation of the lamella connected to it. 

